Microsoft’s diagnosis AI outscored generalist physicians on a set of hard benchmark cases in a peer-reviewed study published Thursday in Science . The results come from a controlled test built on past case records, and Microsoft’s next step is a study with patients at a Boston hospital.

The benchmark draws on 304 complex case records from The New England Journal of Medicine. Running on OpenAI’s GPT-5, the Microsoft AI Diagnostic Orchestrator, or MAI-DxO, reached the correct diagnosis 83.2% of the time. Generalist physicians, who worked through a 56-case subset, scored 36.1% with search and reference tools and 22.3% without them. On 325 emergency department admissions drawn from the MIMIC-IV-ED database, the system scored 80.3% against 46.8% for physicians, Medical Economics reported from the paper.

The setup differs from the preprint Microsoft posted in June 2025.…